Yeah, get on that gents! Those dang Yank aircraft at Pearl Harbor on the ground did't blow up when my Zeke gave them a peppering!
Was commenting that ground objects like the aircraft are an awesome immersion addition. Now, if they only blew up! 
There is a way to simulate it blowing up and burning. It will take some work, but you could make a copy of the plane object, make it destructible with a hardness, give it a "dead" skin (all blackened and such), and then park an ammo bunker under the surface of the plane and make it really soft. That way when you strafe it, the bunker goes up and starts burning, and at the same time the plane turns into a blackened hulk. I did that to a building in a test terrain and it worked (although I haven't strafed it yet - all I did was 'destroy' the objects from the clipboard). I also think there's a way to get it to burn without using a bunker but I haven't got that far yet.
One thing you can't do is animate the polygons that make up a whole object.
I'm working on a bridge where the bulk of the structure is not destructible. But partway over the bridge there's another object, a decking span, that I want to make destructible. So you hit the span with HE or drop a bomb on it, and the skin changes from the 'live' wooden decking with smooth bump map, to a 'dead' span with a see-through skin (making it invisible), and an extreme bump texture that you can't drive over. It's a long process, but it's all been done before on different objects in the main arena.
